8
IM 1131-2
Water Piping
subject to more corrosion than if filled with water. Use of a
Vapor Corrosion Inhibitor (VCI) or some other protection
should be considered.
Figure 4: Thermostat Well Location, WGZ 030 - 130
The chilled water sensor is factory installed in the leaving
water connection on the evaporator. Care should be taken not
to damage the sensor cable or lead wires when working around
the unit. It is also advisable to check the lead wire before
running the unit to be sure that it is firmly anchored and not
rubbing on the frame or any other component. If the sensor is
ever removed from the well for servicing, care must be taken
to not wipe off the heat-conducting compound supplied in the
well.
Flow Switch
A water flow switch must be mounted in the leaving
evaporator and condenser water lines to prove adequate water
flow before the unit can start. This will safeguard against
slugging the compressors on start-up. It also serves to shut
down the unit in the event that water flow is interrupted to
guard against evaporator freeze-up. Factory-mounted and
wired evaporator and condenser flow switches are available as
an option
If the optional factory flow switch is not supplied, a flow
switch is available from Daikin Applied under part number
01750330. It is a "paddle" type switch and adaptable to any
pipe size from 1 in. (25 mm) to 6 in. (152 mm) nominal.
Certain flow rates are required to open the switch and are
listed in
Table 1
. Wire from switch terminals Y and R to panel
terminals 33 and 43 (chilled water) and 41 and 53 (condenser
water). There is also a set of normally closed contacts on the
switch that could be used for an indicator light or an alarm to
indicate when a "no flow" condition exists.
1
Apply pipe sealing compound to only the threads of the
switch and screw unit into 1 in. (25 mm) reducing tee.
The flow arrow must be pointed in the correct direction.
2
Piping should provide a straight length before and after
the flow switch of at least five times the pipe diameter
without any valves, elbows, or other flow restricting
elements.
Table 1:
Paddle-Type Flow Switch Flow Rates
CAUTION
The thermostat bulb should not be exposed to water
temperatures above 125°F (51.7°C) as this will damage it.
Suction
Circuit #1
Suction
Circuit #2
Liquid
Circuit #2
Liquid
Circuit #1
Leaving Chilled
Water Sensor
CAUTION
Make sure the arrow on the side of the switch is pointed in
the direction of flow. The flow switch is designed to handle
the control voltage and should be connected according to
the wiring diagram.
Pipe Size
NOTES (x)
inch
1 1/4
1 1/2
2
2 1/2
3
4
5
6
8
mm
32 (2)
38 (2)
51
63 (3)
76
102 (4)
127 (4)
153 (4)
204 (5)
Min.
Adjst.
Flow
gpm
5.8
7.5
13.7
18.0
27.5
65.0
125.0
190.0
205.0
Lpm
1.3
1.7
3.1
4.1
6.2
14.8
28.4
43.2
46.6
No Flow
gpm
3.7
5.0
9.5
12.5
19.0
50.0
101.0
158.0
170.0
Lpm
0.8
1.1
2.2
2.8
4.3
11.4
22.9
35.9
38.6
Max.
Adjst.
Flow
gpm
13.3
19.2
29.0
34.5
53.0
128.0
245.0
375.0
415.0
Lpm
3.0
4.4
6.6
7.8
12.0
29.1
55.6
85.2
94.3
5455
No Flow
gpm
12.5
18.0
27.0
32.0
50.0
122.0
235.0
360.0
400.0
Lpm
2.8
4.1
6.1
7.3
11.4
27.7
53.4
81.8
90.8
Note (1):
A segmented 3-inch paddle (1, 2, and 3 inches) is furnished mounted, plus a 6-inch paddle loose.
Note (2):
Flow rates for a 2-inch paddle trimmed to fit the pipe.
Note (3):
Flow rates for a 3-inch paddle trimmed to fit the pipe.
Note (4):
Flow rates for a 3-inch paddle.
Note (5):
Flow rates for a 6-inch paddle.
